20. Musical Instruments

  1. Cornet
  2. Trombone
  3. Guitar
  4. Xylophone
  5. Ultrasonic Xylophone - range from the high audible frequencies into the ultrasonics.

  6. Galton's Whistle - range from the high audible frequencies into the ultrasonics.

  7. Organ pipes - one is of variable length to show the dependence of frequency on length.

  8. Sicks - You can play a tune with a set of eight sticks tuned to the major scale by dropping them in the correct order.

  9. Singing tube - when whirled around your head will sound the notes of a major chord.

  10. Siren disk - has four evenly spaced rows of holes yielding a major chord when sounded. The fifth row is unevenly spaced and emits a noise when sounded.

  11. Savart's toothed wheels - will sound a major chord when rotated with a card held against its teeth.

  12. Ultrasonic Receiver - beats ultrasonic signals from a speaker "tweeter", or the Ultrasonic Xylophone (e) or Galton's Whistle (f) in the 20-40 KHz range into audible range.

  13. Music Box - Each tine of the box acts as a simple harmonic oscillator and vibrates at a particular constant pitch. The pins on the box pluck the tines to make them vibrate but the tines alone don't emit much sound. To project sound, the box couples its vibrating tines to a surface.